Identification of a Domain in Yeast Chitin Synthase 3 Required for Biogenesis of Chitin Ring, But Not Cellular Chitin Synthesis

  • Park Hyun-Sook (Department of Biological Sciences, Ewha Womans University) ;
  • Park Mee-Hyun (Department of Biological Sciences, Ewha Womans University) ;
  • Kim Chi-Hwa (Department of Biological Sciences, Ewha Womans University) ;
  • Woo Jeeun (Department of Biological Sciences, Ewha Womans University) ;
  • Lee Jee-Yeon (Department of Biological Sciences, Ewha Womans University) ;
  • Kim Sung-Uk (Research Institute of Bioscience and Biotechnology) ;
  • Choi Wonja (Department of Biological Sciences, Ewha Womans University)
  • 발행 : 2000.10.01

초록

It hab been proposed that CHS3-mediated chitin synthesis during the vegitative cell cycle is regulated by CHS4. To investigate direct protein-protein interaction between their coding products, we used yeast two hybrid system and found that a domain of Chs3p was responsible for interaction with Chs4p. This domain, termed MIRC3-4 (maximum interacting region of chs3p with chs4p), spans from 647 to 700 residues. It is well conserved among CHS3 homologs of various fungi such as Candida albicans, Emericella nidulans, Neurospora crassa, Magnaporthe grisea, Ustilago maydis, Glomus versiforme, Exophiala dermatitidis, Rhizopus microsporus. A series of mutaion in the MIRC3-4 resulted in no appearance of chitin ring at the early G 1 phase but did not affect chitin synthesis in the cell wall after cytokinesis. Absence of chitin ring could be caused either by delocalization of Chs3p to the septum or by improper interaction with Chs4p. To discriminate those two, not mutually exclusive, alternatives, mutants cells were immunostained with Chs3p-specific antibody. Some exhibited localization of chs3p to the septum, while others failed. These results indicate that simultaneous localization and activation Chs3p by Chs4p is required for chitin ring synthesis.

키워드